Containers with detachable and re-attachable lids, including disposable food containers, trays and platters with compatible lids, are well known and are commonly employed in many industries, including food related industries such as restaurants, caterers, institutional food service establishments, cafeterias, and households.
A tray, serving platter, or container base for use in catering and other food service applications frequently features a lid or cover that is cooperatively engageable therewith for presenting, handling, transporting, and/or protecting a variety of food items. The tray or base usually has an upwardly projecting sidewall terminating in a rim. The base or tray rim may simply feature a lip area, or may include sealing ridges, channels or other locking mechanisms that are adapted for cooperative engagement with corresponding grooves, inverted channels, or other cooperative features which are integrated with the lid. Note that the terms “tray” and “base” are used generically herein to refer to any type of tray, serving platter, container, or other support base which is attachable to a lid or cover. Note also that the term “lid” is used generically herein to refer to any type of lid or cover that is compatible with and attachable to a “tray” or a “base”.
Disposable lids for use with food containers and platters are usually thermoformed from a sheet of Polyethylene Terephthalate (PET) or Oriented Polystyrene (OPS) although other plastic materials may be employed. The lid is configured to fit the base, and may include an elevated and/or dome-shaped central portion to allow for comfortably accommodating a certain quantity or height of foods or other contents, and will preserve the shape, form, decorative appearance and/or the general presentation of items such as certain food preparations, including desserts, cakes, sandwiches, or other foods. Or the lid may be substantially flat, and may be attachable to a container which has sufficient depth to surround food items or other contents to be contained therein. In some approaches, once a lid has been engaged with a tray to form a first tray-lid assembly, a second tray-lid assembly can be stacked on top of the first tray-lid assembly, and thus a plurality of tray-lid assemblies can be stacked on top of each other for compact storage and for ease of transportation and handling.
In the case of food containment, it is paramount that food preparations be protected, and that inadvertent disengagement or removal of the lid from the tray be avoided. Therefore, in many cases one or more locking features and/or undercuts are provided at the periphery of the tray and/or the lid, resulting in a relatively tight interference fit between the lid and the tray. However, this tight interference fit can make it difficult for a user to disengage and/or remove the lid at the time of use, resulting in an inconvenience to the user at best, and spilling of the food at worst, as the user struggles to remove the lid from the tray. Depending on the material from which the lid is constructed, the lid may even tear or rip during removal, thereby rendering subsequent reengagement of the lid with tray or container ineffective or futile.
A typical method for disengaging a generic container-lid assembly is by holding the container with one hand and pulling the lid off with the other hand. Sometimes a tab or an indent is provided in either the lid or the container so as to facilitate creating an initial separation or opening between the lid and the container at the location of the tab or indent, and then separating the lid from the container around the entire periphery of the container-lid assembly. However, this method of disengaging or separating a lid from a container can be difficult if the container is shallow, for example if the container is in the form of a tray or plate covered by a lid having a raised portion. In such cases, it can be difficult to grasp the shallow base so as to pull it away from the lid.
A lid having a raised portion, herein referred to generically as a “dome” lid regardless of whether the lid is round, rectangular, or some other shape, may feature a downwardly projecting peripheral skirt that overhangs beyond the perimeter of the tray or container base. As will be appreciated by those skilled in the art, for a relatively shallow tray the overhang of the peripheral skirt of the lid can be almost as tall as the tray, making it even more difficult for a user to grasp the tray for lid removal, and making it difficult even to slide his or her fingers underneath the peripheral skirt of the lid for lifting and carrying of the tray-lid assembly. Instead, a user typically has to lift the tray-lid assembly by the peripheral edge of the lid without touching the tray. In this situation, the entire weight of the tray and its contents is thus borne by the locking or engagement mechanism between the tray and the lid, further necessitating that the tray and lid have a tight fit, which in turn makes it even more difficult to remove the lid from the tray.
A particular difficulty for removing lids from tray-lid assemblies of the type described above is encountered due to the fact that in many cases the lid is flexible and the periphery of the tray-lid assembly is relatively large compared to the size of the tab or indent that is provided with the lid or the tray for initiating separation of the lid from the tray. Consequently, when a user exerts an upward or downward force on the tab or indent provided in the lid or tray for pulling the tray-lid assembly apart, the rim of the lid tends to press opposingly inwardly at other locations, causing the lid to grip even more tightly onto the tray at those locations, and thereby rendering removal of the dome from the tray base extremely difficult, or at least cumbersome.
Thus, there is a need for a lid that is securely engageable with a tray or a container and yet can be conveniently removed from the tray or container with relative ease and without disturbing the contents of the tray or container. These and other needs are met by the lid of the present invention.